1. Field of the Invention
This invention relates to a calcium hydroxide composition and methods for its use on both hard and soft dental tissues.
2. Prior Art
Caustic mixtures of calcium hydroxide have been used in dentistry since the 19th Century as a temporary filling material within the tooth, or as a dental cavity lining material. Concentrated solutions of calcium hydroxide have been used in medicine for treatment of superficial skin wounds and burns of cutaneous skin tissues. More recently, several forms of calcium hydroxide have been used for specific pathological complications inside the tooth in the field of Endodontia.
A review of endodontic use of calcium hydroxide is provided in an article by Martin & Crabb appearing in the British Dental Journal of May 1977 entitled Calcium Hydroxide in Root Canal Therapy.
Generally, recent uses of calcium hydroxide preparations, including pastes, have been limited to dental pulp and root canal therapy. For example, one type of dental cavity lining material that has been particularly successful is disclosed in U.S. Pat. No. 3,047,408 to Dougherty. That patent discloses a dental composition used primarily as a dental cement. The Dougherty dental composition consists essentially of calcium hydroxide in a polyhydric phenol, combined with an ester of salicylic acid to form a calcium phenolate in which an excess of calcium hydroxide is dispersed.
The use of acid resistant, fast curing calcium hydroxide formulations for dental pulp capping and cavity lining has been more recently introduced. U.S. Pat. No. 4,240,832 to Jandourek discloses such a material. The dental material disclosed in U.S. Pat. No. 4,240,832 is prepared by reacting phenolic derivatives with formaldehyde.
Another example of endodontic therapy involving calcium hydroxide is described in the Omaha District Dental Society Journal, page 226 (Manhart). The article describes a method of endodontic sealing which uses a calcium hydroxide paste specifically designed for root canal closure (obliteration).
In addition, studies by Green, Green and McPhall in the Journal of Peridontology, 1977, Oct. 48(10), p. 887-72 on the treatment of hypersensitive root surfaces reinforce the potential value of calcium hydroxide preparation in endodontic therapy. Likewise, a method of using calcium oxide and water to form calcium hydroxide as a permanent endodontic filler is described by Donnelly and Harty in the Journal of the British Endodontic Society (1979).
Therefore, it is evident that calcium hydroxide has been extensively studied as a potentially valuable agent in controlling endodontic problems. However, the prior art teaches away from using calcium hydroxide in periodontal therapy. An example of such art can be found in the Dental Clinics of North America Journal of October, 1979, Vol. 23 p. 691-703 (Frank) on calcium hydroxide uses in dentistry. As shown in the Frank Article, the conventional experience is that calcium hydroxide pastes are too strong for the soft gingival or periodontal tissues. Accordingly, there is a need for a calcium hydroxide material which is formulated to control its strong alkaline properties so that it can be safely used on soft gingival and periodontal tissues.
Along with the need for the dental material, there is a corresponding need for methods for using the calcium hydroxide paste for treating soft tissue, bacterial infections and a variety of other dental complications. Nowhere in the dental literature or reference patents is there disclosed a comprehensive method of periodontal therapy using a controlled form of calcium hydroxide paste. The instant invention is directed toward these needs.